1. Field
The present invention generally relates to an image processing system, and more particularly to an image processing system and method for automatically controlling the gains for color flow images.
2. Background
An image processing system, which is used for processing an image of a target object and displaying the processed image, has been widely used. By way of an example, an image processing system for performing ultrasound diagnosis (hereinafter referred to as an “ultrasound diagnostic system”) will be described.
Generally, an ultrasound diagnostic system has become an important and popular diagnostic tool due to its wide range of applications. Specifically, due to its non-invasive and non-destructive nature, the ultrasound diagnostic system has been extensively used in the medical profession. Modern high-performance ultrasound diagnostic systems and techniques are commonly used to produce two or three-dimensional (2D or 3D) diagnostic images of a target object. The ultrasound diagnostic system generally uses a probe including an array transducer having a plurality of transducer elements to transmit and receive ultrasound signals. The ultrasound diagnostic system forms ultrasound images of the internal structures of the target object by electrically exciting the transducer elements to generate ultrasound pulses that travel into the target object. The ultrasound pulses produce ultrasound echoes since they are reflected from a discontinuous surface of acoustic impedance of the internal structure, which appears as discontinuities to the propagating ultrasound pulses. Various ultrasound echoes return to the array transducer and are converted into electrical signals, which are amplified and processed to produce ultrasound data for forming an image of the internal structure of the target object.
Especially, a conventional ultrasound diagnostic system provides color flow images showing the velocities of a moving object and scatters. In the color flow images, the velocity and direction of the moving object such as blood flow in the heart or blood vessel are represented in various colors based on Doppler shift. For example, the following conventional method is used to interpret the above images: blood flow moving toward the probe is represented in red; blood flow moving away from the probe is represented in blue; fast blood flow is represented in light color; and slow blood flow is represented in dark color. Accordingly, it is possible to accurately visualize the blood flow in real time.
However, in the color flow images provided by the conventional ultrasound diagnostic system, a width of blood flow in the blood vessel may seem thinner or thicker than that of the vessel. In order to correct this, the gains for the color flow images should be controlled minutely, wherein such gain control is conducted manually. Therefore, the user has to perform a complicated operation to minutely control the gains for color flow images. Thus, the time required for diagnosis becomes longer.